Case report: A case of polypoid endometriosis: MR pathological correlation.

We report a case of polypoid endometriosis and correlate the MRI findings with the pathological findings. The polypoid endometriosis appeared as multiple polypoid masses protruding into the adjacent pelvic organs, including the uterus and rectum. The masses were found to show hyperintensity on T(2) weighted images, which was similar to the signal intensity of the uterine endometrium, reflecting the presence of abundant endometrial-type glands. The masses were also surrounded by hypointense rim-like structures on T(2) weighted images. These structures were confirmed by pathology to correspond with fibrous tissues arising from endometriosis. These features, together with an intense enhancement similar to the adjacent uterus, may be a diagnostic clue to this rare entity.